How many resources?

How many resources are defined in the following Docker Compose file?

services:
  redis:
    image: redislabs/redismod
    ports:
      - '6379:6379'
  flask:
    image: flaskapp
    ports:
      - '8000:8000'
    depends_on:
      - redis
  nginx:
    image: nginx
    ports:
      - '80:80'